Electrical Properties and Structure of p‐Type Amorphous Oxide Semiconductor xZnO·Rh₂O₃

Abstract

p‐Type conduction in amorphous oxide was firstly found in zinc rhodium oxide (ZnO·Rh2O3) (Adv. Mater. 2003, 15, 1409), and it is still the only p‐type amorphous oxide to date. It was reported that an ordered structure at the nanometer scale was contained and its electronic structure is not clear yet. In this paper, optoelectronic and structural properties are reported in detail for xZnO·Rh2O3 thin films (x = 0.5–2.0) in relation to the chemical composition x. All the films exhibit positive Seebeck coefficients, confirming p‐type conduction. Local network structure strongly depends on the chemical composition. Transmission electron microscopic observations reveal that lattice‐like structures made of edge‐sharing RhO6 network exist in 2–3 nm sized grains for rhodium‐rich films (x = 0.5 and 1.0), while the zinc‐rich film (x = 2) is completely amorphous. This result indicates that excess Zn assists to form an amorphous network in the ZnO–Rh2O3 system since Zn ions tend to form corner‐sharing networks. The electronic structure of an all‐amorphous oxide p‐ZnO·Rh2O3/n‐InGaZnO4 junction is discussed with reference to electrical characteristics and results of photoelectron emission measurements, suggesting that the p/n junction has large band offsets at the conduction and valence bands, respectively.

Optical Properties and Electronic Structure of Spinel ZnRh2O4

“…This correspondence means that the band positions are accurately determined by the LDA calculations. Based on our electronic structure calculations and comparison with previous studies, 5,15,17,18 we assign the feature centered at ∼2 eV to a Rh 3+ d f d (t 2g to e g ) on-site excitation. This symmetry forbidden transition is made possible due to crystal-field splitting of the Rh 4d orbitals and the hybridization of Rh d and O p states.…”

Optical and Carrier Transport Properties of Cosputtered Zn–In–Sn–O Films and Their Applications to TFTs

“…This structure remains partly in amorphous InGaZnO 4 , 33 and In-Zn-O, 34 and the portion of the edge-sharing structures decreases with decreasing In content, and the edge-sharing structures are converted to corner-sharing ones. As we pointed out in the amorphous Zn-Rh-O system, 35 an edge-sharing structure has a much stronger geometrical constraint to form an amorphous structure, and the increase in corner-sharing structures would form a more stable amorphous structure. We speculate that the increase in Zn content in a-ZITO films and probably also in other AOSs increases corner-sharing structures, forms a more stable amorphous structure, and reduces D it .…”

A New Highly Conductive Direct Gap p-Type Semiconductor La1–xYxCuOS for Dual Applications: Transparent Electronics and Thermoelectricity

“…The schematic drawing of such equivalent circuit is shown in the inset of Figure a, and a parallel resistor R p was added to serve as the current leak path. The relation of the diode current I d with the applied voltage V a can be represented by the following equation where I 0 is the reverse saturation current, R s is the series resistance with the diode, and n is the ideality factor. By fitting the abovementioned equation for the two diodes in the equivalent circuit to our measured I – V characteristics, the various parameters including R p , R s , I 0 , and n could be estimated (Table S4).…”